The related application Ser. No. 10/298,938 describes a method and apparatus for spreading traffic among routers in a packet network by causing routers in an autonomous system to send traffic over a border router capable of forwarding traffic to its intended destination that is different from the border router having the least cost path that is capable of forwarding traffic to its intended destination.
To cause the routers in an autonomous system (AS), which is a portion of a network under administrative control of a single entity, to send traffic over a border router capable of forwarding traffic to its intended destination that is different from the border router having the least cost path that is capable of forwarding traffic to its intended destination, ranges of addresses advertised by at least two border routers as the ranges of addresses to which they are able to forward communications are reallocated among the routers and optionally, split, causing traffic for that range of addresses to be carried by more than one border router.
This technique can help alleviate the overloading of links caused by a relatively large volume of traffic received by one router that is sent outside the AS, such as when circuit traffic is carried over a packet network such as the Internet. Instead of the normal case in which a router receives a small (relative to the total it receives) amount of traffic for each of many destinations which end up being served by routers dispersed throughout the AS, when a large amount of traffic is received for a small number of one or more destinations, it can cause one or more links to those one or more destinations to become over-utilized, which can increase delays through the network.
However, there is another use for this technique. If it is possible to identify links that have a high utilization and identify the source of the traffic causing such high utilization, the technique described in the related application Ser. No. 10/298,938 could be applied to that source and the address ranges corresponding to destination addresses causing the high utilization of links, which could serve to more evenly spread the utilization of links in the AS. However, it could also shift traffic to links that, although not over-utilized before, become over-utilized as a result of the application of the technique.
What is needed is a system and method for identifying ranges of addresses on which the technique described in the related application Ser. No. 10/298,938 could be used to reduce utilization of the highest-utilized links, and for analyzing the effect of causing traffic to use a path other than the least cost path in an autonomous system.